The invention relates to the field of oxygen-enriched combustion, and discloses an oxygen-enriched combustion system and method. The oxygen-enriched combustion system comprises a boiler (101) and a coal mill (104). An inlet of the boiler (101) is communicated with an outlet of the coal mill (104). The oxygen-enriched combustion system is characterized in that the temperature of mixed gas entering the coal mill (104) is higher than the moisture condensation temperature of acid gas in the coal mill (104); and the oxygen concentration of the mixed gas entering the coal mill (104) is lower than the critical value of the oxygen concentration of the mixed gas causing detonation of coal powder and/or combustible gas in the coal mill (104). According to the oxygen-enriched combustion system, moisture condensation corrosion of the acid gas in the coal mill (104) can be prevented, and meanwhile the problem of spontaneous combustion of coal powder in the coal mill (104) in the boiler shutdown process can be effectively prevented. The equipment running safety is improved, and the service life of equipment is prolonged.